The Effect of Temperature on the Viscosity of Liquids Break

Introduction

Ostwald viscometer, also known as U-tube viscometer or capillary viscometer is a device used to measure the viscosity of the liquid with a known density. The method of determining viscosity with this instrument consists of measuring the time for a known volume of the liquid (the volume contained between the marks A and B) to flow through the capillary under the influence of gravity. Ostwald viscometers named after the chemist Wilhelm Ostwald.

Wilhelm Ostwald, in full Friedrich Wilhelm Ostwald, (born Sept.

2, 1853, Riga, Latvia, Russian Empire—died April 4, 1932, near Leipzig, Ger.), Russian-German chemist and philosopher who was instrumental in establishing physical chemistry as an acknowledged branch of chemistry. He was awarded the 1909 Nobel Prize for Chemistry for his work on catalysis, chemical equilibria, and chemical reaction velocities.

Background Information

The viscosity of liquid is a resistance to flow of a liquid. All liquids appear resistance to flow change from liquid to another, the water faster flow than glycerin, subsequently the viscosity of water less than glycerin at same temperature.

Viscosity occurs as a result of contact liquid layers with each other. The viscosity is measuring by Ostwald viscometer.

Relative Viscosity is the ratio of the absolute viscosity of the fluid on the viscosity of water at a certain temperature.

The viscosity coefficient is force (dyne) necessary to move the layer of liquid 1 cm2 in speed 1 cm/sec on another layer of liquid and the distance between them is 1cm.

Viscosity of fluids varies with pressure and temperature. For most fluids the viscosity is rather sensitive to changes in temperature, but relatively insensitive to pressure until rather high pressures have been attained.

The viscosity of liquids usually rises with pressure at constant temperature. Water is an exception to this rule; its viscosity decreases with increasing pressure at constant temperature.

For most cases of practical interest, however, the effect of pressure on the viscosity of liquids can be ignored. Temperature has different effects on viscosity of liquids and gases. A decrease in temperature causes the viscosity of a liquid to rise. Effect of molecular weight on the viscosity of liquids is as follows; the liquid viscosity increases with increasing molecular weight.

An inks’ viscosity has the ability to affect almost every aspect of your printed product from color strength, graphic quality, ink thickness, density, ink usage, press speed, drying time.

Printers use a distinguished viscosity of ink to function appropriately. Printers produce heat due to electrical and mechanical effect. Especially when printers stay in use for long time without pause, the heat produced as lose of energy becomes very high. This temperature change can affect the entire machine by heat up. Sometimes printers stop working when they become over heated, but some time instead of stop functioning they start out putting inappropriately. The ‘bad’ out puts are usually not dry and their graphics quality is also poor. This might be related to the heat produced and the viscosity of the ink that is inside the printer. This made my investigation to take place.

Variables

Dependent variable:

Temperature of the two liquids, the ink and the water, was varied (30, 40, 50, 65, and 80).

Independent variable:

The time taken for the liquid to move down through the capillary tube was my independent variable.

Controlled variable:

The length of the capillary tube which was marked to measure the time taken was controlled. I controlled this by putting two black marks on the tope, where the liquid start flowing, and the bottom, where the liquid end flowing. This is important because of the distance-time invers proportionality. If the distance is varied the time also changes inversely to the distance. Hence, the data I collect could not be accurate and, even, precision.

Apparatus and chemical used:

1.

1

11

2. Ink

3. Thermometer

4. Water

5. Siring

6. Pipette

7. Ostwald viscometer

8. Hot plate

9. Ruler

10. Graduated cylinder

11. Electronic balance

12. Beaker

13. Standing clamp

Procedure

1. I cleaned the viscometer by the water and ethanol and dry it. Because I used new Ostwald viscometer was not necessary to clean by using alcohol and water. The important of using water is to remove polar substances and alcohol is for the removal of nonpolar substances like oil.
2. Put a certain amount of liquid (water and the two different types of ink) in the large bulge viscometer and pull it by pipette until the small bulge is full. When I changed the inks the viscometer washed very well to avoid contamination. The viscosity of a particular liquid could be affected by other substances which have different viscosity. Since the two inks that I have used have different viscosity, I needed to be careful to avoid formation of mixture.
3. Put viscometer vertically in the water bath at the desired temperature. At this step I needed to make sure that the Ostwald viscometer is vertically stood. This is show in the figure 1.0 below in the experiment setup.
4. Using a pump I pumped the heated liquid to the upper section of the Ostwald viscometer which has larger proportion of space to keep the liquid until the pump realised off. The figure below show the parts of an Ostwald viscometer from http://www.wikiwand.com.
5. Let the liquid to flow through the capillary tube with run time when the liquid reaches the mark shown on the viscometer and then stopped time when the liquid reaches the bottom mark.
6. Repeated the experiment five times and record the results (I took the average result).
7. Stapes 1-6 repeated to experiment ink.
8. Change the temperature and calculate the viscosity.

Safety, Ethical or Environmental Issues

The investigation only going on by changing the physical state of different inks; this has no any effect on the health if I touched them. Yet the inks have possible effect if I contacted them to my eyes. To avoid this being careful was enough. Besides, the inks are environmentally safe. But to remove any casualty I removed the used ink appropriately.

The heater that I have used uses a pipe to transfer in to and out of the heater. This pipe at high temperature could explode and splash hot water to the surrounding. This may cause face burn; so it better to careful. I have experienced it without any safety kit. But, after that, I started to control the temperature to the limit of the pipe expansion.

Data analysis:

Table 1: The data collected for the time taken when water passes through the viscometer in the selected temperatures

water

Temperature ± 0.5

time/ seconds ± 0.01

trial 1

trial 2

trial 3

trial 4

trial 5

average

percentage uncertainty

30

11.28

11.07

10.38

11.06

11.17

10.99

± 0.09%

40

10.28

10.81

9.01

10.59

10.68

10.27

± 0.10%

50

8.42

9.33

9.10

9.12

9.19

9.03

± 0.11%

65

8.66

8.02

8.31

8.68

8.39

8.41

± 0.12%

80

7.58

7.58

7.86

7.94

7.90

7.77

± 0.13%

The formula showed on the introduction tells us the method is only helping us to find the ratio of two different liquids. The two different liquid represented as and the ratio is represented as. This led us to make the new liquid, ink, to be the subject of the formula (). But we used secondary data for the viscosity of water,, as table 2 show us below.

Table 2: Data for the viscosity of water

Temp. [°C]

Dyn. Viscosity [mPa.s]

Kin. Viscosity [mm²/s]

30

0.7972

0.8007

40

0.6527

0.6579

50

0.5465

0.5531

65

0.4329

0.4415

80

0.354

0.3643

· NB. I used the kinetic viscosity from the table.

Table 3: show the density for the liquids I used in the investigation

mass/g

volume/cm3

density/ kg/m3

percentage uncertainty

yellow ink

10

10

1000

± 7

pink ink

10

10

1000

± 7

water

10

10

1000

± 7

Table 3: The data collected for the time taken when yellow ink passes through the viscometer in the selected temperatures

yellow ink

temperature ± 0.5

time/ seconds ± 0.01

trial 1

trial 2

trial 3

trial 4

trial 5

Average

percentage uncertainty

30

18.74

18.36

18.69

18.68

18.58

18.61

± 0.05

40

16.48

16.36

16.27

16.43

16.13

16.33

± 0.06

50

14.46

14.20

14.48

14.52

14.12

14.36

± 0.07

65

12.15

12.25

12.16

12.50

12.48

12.31

± 0.08

80

11.14

10.93

10.80

10.86

10.89

10.92

± 0.09

Example: for the uncertainty of time at 300C

Hence I found the time take of the yellow ink, the next step was finding out the density of the two liquids (water and ink). To find this I used simple method which was that mass divided by volume. For all liquid I found the same density, 1000Kg/ m3 with the uncertainty of ± 7 %. The uncertainty became quit large, because of the graduated cylinder that have used. After this calculating the viscosity of the first ink became possible to calculate. The result is displayed on the table below.

Table 4: this table show us the viscosity of the yellow ink related to temperature

Temperature/ oc viscosity of yellow ink percentage uncertainty actual uncertainty

30

1.36

14.14

0.19

40

1.05

14.16

0.15

50

0.88

14.18

0.12

65

0.65

14.20

0.09

80

0.51

14.22

0.07

The result comes be using the formula given in the introduction (). For example: at 300C the average time take recorded for water was 10.99 and for the yellow ink was 18.61. Addition to that, the density of both liquids was 1000 Kg m3. Then the uncertainty of each value was calculated using the following formula:. Following this we drew graph to find out the relationship.

Example for the viscosity I got for yellow at 300C

Since I have the percentage uncertainty, adding up all uncertainty is helpful to find it.

Graph 1: this show us the relationship between temperature change and viscosity of an ink

The relation y=mx + b is the relation of the graph for the relation of water viscosity and ink viscosity. The gradient of the graph is m which is the ratio for (the two liquids). The formula has described on the way of y=mx + b.

Y is the subject of the formula like

X is the horizontal value that replace

“m” is the gradient of the graph that show the value of

“b” is a Y intercepts; means the value of Y when X is Zero, but I do not have zero value

The above two graphs show us the effect of temperature on two different colour viscosity. The one on the left is a graph for yellow ink and the one on the right is for pink ink. The graphs have a negative correlation. This means the effect of temperature on the viscosity of inks is opposite to the change in viscosity (As the temperature increases the viscosity of inks decrease). In theory different types if inks has different viscosity and the effect of temperature also different. On the above graphs, the effect of temperature on every ink is different, but the change that comes due to temperature change in general is similar.

Conclusion

The investigation was about finding out the effect of temperature on the printer’s inks. The investigation mainly takes out temperature, because the heats produce by over using printers. And by the observation of printer’s misbehaving I tried to find out if the problems are actually from overheating.

In theory, the quality of a printout is mainly determined the viscosity of the ink we are using. In order to crate best print out factories work on the standard viscosity of ink, also they advise to keep the ink in room temperature. The speed of printing, the graphics of the printout, and the speed of drying and additional properties of papers are dipped on viscosity.

The result of the investigation showed me that the viscosities of inks are affected by the temperature. As the temperature raises the viscosity of inks reduced. This showed on the graph 2 that the relation of ink viscosity and temperature has a negative correlation.

The investigation done by comparing with the viscosity of water and inks: water has low viscosity compare to the rest of liquid substances. The resistance to get dry and also the speed of flow are common characteristics due to its viscosity.

The waters properties come to inks when the temperature rises and the viscosity reduced. So the heating up of printers due to electrical and mechanical effect affect the quality of the print out.

The change in viscosity as the temperature of the surrounding increases. This has not effect on the quality of the print out only! The in

Increase in temperature has also increases the consumption of ink as the viscosity increases. This research has done by the cooperation of Western Michigan University and Design for the environment organisation. Graph three shows the relation between consumption of ink due to temperature increase. As a result of consumption increase the money invested to buy inks also increases which in wastage of resource and money. Keeping the power off until signal of command to print come can help us to reduce energy and ink consumption. This can be done by using electric and wave, for Wi-Fi, detectors.

Based on sources, the newly produced printers are able to adjust the viscosity of the inks when they become over or below the standard viscosity. This supported my conclusion. Over using causes over heating then over heating causes to reduce viscosity and this results poor quality of printout and west of ink.

Evaluation

Possible sources of error

• The apparatus I was using could be a possible source of error
• The secondary data that I have used for the viscosity of water possibly has error, yet it is not included in this investigation.
• Observing the flow of liquid from the upper mark to the lower would be a cause for error.
• Controlling the temperature was challenging; when, sometimes, the temperature comes over from the expected temperature the result become inaccurate.

Amendments of possible sources of error

• In order to reduce error that come from the apparatus used, instead of using measuring devices using digital devices are more preferable to reduce reading error and getting more presided data.
• Keep going with the rules of experimenting to reduce error also helped me to reduce error caused by observation.
• The secondary data that I have used was from trusted web site. The research work has more acceptances by education people. Hence the error caused by the data would be lower.

Additionally, the method of using Ostwald viscometer meter is chosen because:

• The investigation is using printer’s inks which are quite expensive. Using Ball-Drop experiment cost a lot of money to buy inks. Hence I prefer to use Ostwald viscometer experiment. This idea was suggested by SOS HGIC physics lab assistance, Mr Abu.
• Ink is sticky on the surface of substances and it is not good transparent. Since it has these properties, the method of Ball-Drop is not applicable in this particular experiment. Because the observation couldn’t be accurate.

Reference

1. “Thomas Scientific.” At Thomas Scientific, www.thomassci.com/scientific-supplies/Ostwald-Viscometer.
2. Lee, Christina. “Who First Discovered Viscosity?” Sciencing, 21 Nov. 2017, sciencing.com/first-discovered-viscosity-17922.html.
3. A Modified Ostwald Viscometer.” C&EN: WHAT'S THAT STUFF? JELL-O, pubs.acs.org/doi/abs/10.1021/ed050p194.
4. Schummer, Joachim. “Wilhelm Ostwald.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 29 Mar. 2018, www.britannica.com/biography/Wilhelm-Ostwald.
5. 2009, Andrea Sella29 May. “Classic Kit: Ostwald's Viscometer.” Chemistry World, 29 May 2009, www.chemistryworld.com/opinion/classic-kit-ostwalds-viscometer/3004929.article.
6. “Determining the Molecular Weight of a Polymer from Intrinsic Viscosity Measurements.” Specific-Charge-of-the-Electron-e-m, www.phywe.com/en/determining-the-molecular-weight-of-a-polymer-from-intrinsic-viscosity-measurements.html